Lock



FIG. 1 is a back view of a lock showing my new design;

FIG. 2 is a left side view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is top view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a front perspective view thereof; and,

FIG. 7 is a bottom view thereof. 

CLAIM The ornamental design for a lock, as shown and described. 